Distribution characteristics of pathogenic bacteria from diabetic foot ulcer of patients with different Wagner grades

Abstract:

ObjectiveTo understand the distribution and drug resistance  of pathogenic bacteria from diabetic foot patients of different grades of Wagner classification, and provide basis for the rational use of antimicrobial agents in clinical practice. MethodsClinical data, pathogens isolated from wound secretion, and antimicrobial susceptibility testing result of diabetic foot patients who were admitted in the department of endocrinology in a hospital between January 2014 and December 2016 were analyzed retrospectively, patients were divided into grampositive (G+) bacteria infection group, gramnegative (G-) infection group, and mixed infection group according to the isolation of bacterial species, relationship between patients’ clinical characteristics and Wagner grades was analyzed. ResultsThere were 103 patients with diabetic foot, 39 with G+ bacterial infection, 50 with G- bacterial infection, and 14 with mixed infection. The age and disease course of patients with mixed infection was significantly elder and longer than the other two groups of patients(both P<0.05); glycosylated hemoglobin (HbA1c) and procalciton in mixed infection group were both lower than the other two groups(both P<0.05); the percentage of neutrophils in G+ infection group was higher than the other two groups（P＜0.01）. A total of 132 specimens were detected, 103 strains were isolated, the positive rate was 78.03%, isolation rates of G+ and G- bacteria were 33.33% (44/132) and 44.70% (59/132) respectively. The major G+ strains were Staphylococcus aureus(n=19) and Staphylococcus epidermidis(n=11), the major G- bacteria were Citrobacter braakii(n=12), Escherichia coli(n=11), and Pseudomonas aeruginosa(n=11). As the Wagner grade increased, the proportion of mixed infection continued to rise. The main multidrugresistant organisms were methicillinresistant Staphylococcus aureus  and extendedspectrum betalactamaseproducing G- strains. ConclusionFor diabetic foot patients, especially those with higher Wagner grades, etiological examination and antimicrobal susceptibility testing of ulcer secretion should be timely performed, so as to provide reference for rational use of antimicrobial agents in clinic.